[emacs-bidi] branch emacs-bidi is created

[Kenichi Handa]

I've just made a branch "emacs-bidi" and commited several
changes including Eli's bidi code so that people other than
I can start working on it.

But, although I can compile the code and start up Emacs,
when I set the buffer local variable enable-bidi-display,
Emacs crashes.   Eli, I need your help.

In the reseat_1 (in xdisp.c), I put this code.

  if (it->bidi_p)
    {
      bidi_init_it (pos.charpos, L2R, &it->bidi_it);
      bidi_get_next_char_visually (&it->bidi_it);

      pos.charpos = it->bidi_it.charpos;
      pos.bytepos = it->bidi_it.bytepos;
      it->current.pos = it->position = pos;
    }

But, as bidi_init_it doesn't set bidi_it->ch_len,
bidi_get_next_char_visually sets it->bidi_it.bytepos to less
than it->bidi_it.charpos.

bidi_init_it has this code:

bidi_init_it (int pos, bidi_dir_t dir, struct bidi_it *bidi_it)
{
  if (! bidi_initialized)
    bidi_initialize ();
  bidi_set_paragraph_end (bidi_it);
  bidi_it->charpos = pos;
  if (pos <= 0)
    {
      bidi_it->bytepos = bidi_it->charpos;
      bidi_it->ch_len = 1;      /* so that incrementing bytepos works */
    }
  else
    bidi_it->bytepos = CHAR_TO_BYTE (pos);

As POS is always greater than 0 when we are scanning a
buffer, bidi_it->ch_len is not set.

---
Ken'ichi HANDA
address@hidden